“[O]ne who does not feel any holiness within himself at all
can be sure that he does not possess even* a neshama;
he has no contact with the neshama, for it has completely
left him. It will return only if and when he does teshuva.”
-Strive for Truth, vol. 1, page 211. Rav Dessler says this in the name of
his rebbi – I think he was Rav Tzvi Hirsch Braude (son of the Alter of Kelm).
*An earlier part of the paragraph was about the neshama yeseira of Shabbos.